<div dir="ltr"><br><br><div class="gmail_quote"><div dir="ltr">On Mon, 16 May 2016 at 16:13 Matthias welp <<a href="mailto:boekewurm@gmail.com">boekewurm@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div>I won't comment on the content of this proposal, as I'm don't really see the implications, but I would like to correct one small mistake:<br><br></div>Under 'performance impact' you say this:</div></div></div><div dir="ltr"><div><div><br><br>>
In terms of memory impact, since there are typically not many CPython
interpreters executing in a single process that means the impact of
co_extra being added to PyCodeObject is the only worry. According to <a href="https://github.com/Microsoft/Pyjion/blob/master/pep.rst#code-object-count" rel="noreferrer" target="_blank">https://github.com/Microsoft/Pyjion/blob/master/pep.rst#code-object-count</a>,
a run of the Python test suite results in about 72,395 code objects
being created. On a 64-bit CPU that would result in 4,633,280 bytes of
extra memory being used if all code objects were alive at once and had
nothing set in their co_extra fields.<br><br></div></div></div><div dir="ltr"><div><div></div>The extra RAM used is a bit off. One 64-bit pointer extra takes only 8 bytes, which translates to about <span>579160 bytes extra used in in the test suite. I did not consider padding for accessibility, but that was also not considered in the draft.<br></span></div></div></blockquote><div><br></div><div>Oops, my mistake. Thanks for pointing it out!</div><div><br></div><div>-Brett</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><span><br></span></div></div><div dir="ltr"><div><span>-Matthias<br></span></div><span></span></div>
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